Mounting for vertically movable tandem wheels



Oct 21, 1952 E. F. NoRELlus MOUNTING FOR VERTICALLY MOVBLFrv lTANDEM WHEELS original Filed March 2'. 1949 al..M kw

f Patented ct. 21, .1952

" MOUNTING FOR VERTIOALLY MOVABLE TANDEM WHEELSY Emil F. Norelius, l Springfield, Ill. assignor to Allis-'Chalmers Manufacturing Company, Mily waukee, \Wis.,\ a' corporation of Delaware Original application March25, 1949, Serial No. 83,361. Divided and this application December 14, 1949, Serial No. 132,939 1 7 Claims.

1 The invention relates to' vehicle running gear and it is concerned more particularly with an improved tandem drive mechanism Vfor motor vehicles The present application is a divsion of application Serial NO.83,36l,"led onlMarch 25, 1949,

'"Afurther object'of the invention's to provide' an improved mounting for. the vertically movable tandem wheel. 3' These and other objects and advantages are attained by the present invention, various novel features of which will be apparent from the description hereinand the accompanying drawings disclosing an embodiment of the invention, and will be more particularly pointed out4 in the accompanying claims.

In the drawings:` Y .v y Fig. 1 is a diagrammatic side View ofa four wheel drive tractor, front and rear wheels at the nearside of the tractor being omitted for purposes of exposure;

Fig. -2 is a top View of a; link and other parts at the near side Vofthe tractor shown in Fig. 1, portions of the link and associated parts inFig. 2being shown in section on line II-II of Fig. 1; Fig- 31s asectional view, on line AIII--III in Fig. l, of a tandemdrive mechanism `at thenear side of the tractor shown in Fig. l; andVv Fig.4-is a schematic front view of the running gearvandvpart of the-main body of the tractor showninFig. 1. v Y l Referring to Fig. 1, .the running gearv of the tractor/comprises a pair of tandem Wheels W1 and W2 at the far side of the tractor, and a corresponding: pair oftandem wheels at the near sideof the tractor,vshown in Figs. 2 and 3. 1 The main body ofthe tractor .is generally indicated in Figs. 1 and 4 by the reference character 3, and the rear tandemwheels W1 are rotatably mounted, .asiwill be more fully explained hereinbelow with reference toFig.' 3, at the opposite ends of a transverse rear axlehousng 4, Which forms part Ofthe'main'body 3. As indicated in Fig. 1, and as more learly-shown in Fig. 4, a transversen leaf springVBV extends between the front tandem wheelslWz and is Vpivoted'at its center on a; forward'part ofthe-main body 3 by meansoi apin- 5 which extends horizontally in the longitudinal direction of the tractor. The spring 6 is rockable on the axis of the pin V5 in conformity with well known principles as disclosed forfinstan'ce in my U. S. Patent 1,429,449, dated September'19, 1922, for Main Frame and Suspension for Tractors.

As shown in Fig. 1, a supporti forfthe'near front tandem Wheel W2 is vconnected with the rear axle housing 4 by means of an upper link 8 and a lower link 9, and a corresponding support 'I (Fig. 4) is similarly connected by means of an upper and a loWer link to the rear axle housing 4 at the far sidev of the tractor for mounting the other front tandem wheel Wz'as shown in Fig. 4, the opposite endsof transverse leaf spring 6 are connected in vertical load `transmitting relation with the Wheel supports 1. respectively, so as to sustain the main body 3 forwardly of the rear tandem Wheels W1-on the front tandem Wheels W2 and permit-up Aand down swinging movement of theffront tandem wheels independently of each other relative to the main body 3. l f Y Referring to Fig. 2, the upper link 8 is constructed in the form of a tapered frame Vhaving a relatively Wide rear end and a narrow front end, ball and socket joints Hand l2 pivotally connecting the wide rear end of the link 8 with a pair of transversely spaced upper lugs I3 and i4 on the reary axle housing 4, and a-Htransve'rse pivot pin -I6 connecting the narrow frontend of the link 8 With'a pair of upper lugs l1 on the Wheel support `1. f 1;1g-q,

The lower link 9 is preferably constructed'in the form of a rod having ka ball and socketconnection I8 at itsrear end with a lower lug lI9 of therear axle housing 4, anda ball .and socket connection` 2| with a .lower lug on the'wheelsupportl. W f ,n

From the foregoingl description 'of the vcon'- struction and mounting of the upperand lower links 8 and 9, it will be seen that the' links8-an'd 9, at the near side of the rtractorconnectthe wheel support 1 vin vertically movable-relation with the axle housing 4, and that thev wheelsfupport 1 is properlystabilized againstftoeing-ih and out and against lateral-tilting1rlativef`-to the main body 3. That is, lateral thrust-'forties to which the near Wheel W2 on thegvvheel support 1 becomes subjected duringoperationof the tractor, particularly duringjlturni `r1g,` which tend to push thevvheel anduitsjr support 1 toward 01 P1111 it awavlfrQmhgtractor lmn body. will be taken up bythe link 8 Aandy itsipivot of the wheel.

The Wheel support 1 at the far side of the tractor (Fig. 4) is constructed and mounted in the same manner as the wheel support 1 at lthe near side of the tractor.

Referring to Fig. 3, an annular casing 22 which forms part of the rear-axle housing 4, Yhas a large axial end aperture, and a cover. 23 for said aperture is rigidly secured to the casing 22 and has a central hub sleeve 24 which extends axially outward from the casing` 22. The rear tandem wheel W1 is rotatably mounted on the hubfsleeveV 24.i n axially xed position' byconical roller bearings A26 and 21. lA quill shaft 28 which extends axially through the hub sleeve 24 and which is rotatable relative to the latter and relative tothe wheel W1, has a circumferential series of axially extending splines formedY at its axially inner end. A bevel gear A is nonrotatably connected with the splined axially inner end ofthe quill shaft 28 within the casing 22, and the hub of the bevel gear A is rotatably mounted in the cover 23 and in a web 23 of the casing 22 by means of a roller bearing 38 and a double row ball bearing 3|.

The rear axle housing 4 encloses a suitable power steering mechanism which is not shown but which, for instance, may be of the type generally used in crawler tractors for eifecting steering by controlling the drive to the traction devices at the opposite sides of the tractor body.

As shown in Fig. 3, a rotatable drive shaft S extends axially through the quill shaft28, and the axially outer end of the drive Vshaft S is mounted in axially fixed position on the rear Wheel W1 by means of a ball bearing 25 for rotation relative to the rear wheel and relative to the quill shaft 28. The mentioned power steerrlgpmechanism` (not shown) which is enclosed within the rear axle housing 4, is operable to control ,the transmission of engine powerto the drive shaft S. y

Vintegrally formed with the drive shaft S at the axially outer end of the latter is an externally toothed gear X which forms the` sun `gear of an epicyclic gear train1 within therear wheel 'WL A diskYwhichis rigidly ysecured atits outer periphery to the rim of the rearfwheel W1 forms the spider of the mentioned epicyclic gear train, and a ringgear Z which is rigidly connected-with the axially outer end of the quill shaft28 vby means of a flange structure 32 forms ,a counter gear of ythevmentioned epicyclic'gear train. A circumferential series `of studs 33 are secured to the spider Y, and spur gears P which form planet pinions ofthe mentioned epicyclicvgear train are rotatablymounted on the studs 33, each planet pinion meshing with the external teeth of the sun, gear X Yand with the internal teeth of the ring gear Z.

. As shown in the upper half of Fig. 3, a line shaft `34 is rotatably mounted on the casing 22 for rotation on an axis at right angles tothe axis of the lrear wheel W1, the line shaft 34 being -rotatably supported in axiallyfixed position `by means of a rollerbearing 35. andiabalhbearing 31 in an annular bearing support 38 which is rigidly secured to the casing 22 at the forward side of the latter. Integrally formed with the line shaft 34 is a bevel gear B which meshes with the bevel gear A within theA casing 22.

The support 1 for the front wheel W2, as shown in Fig. 3, comprises a casing 4| and a cover 42 therefor which has a tubular central hub sleeve 43 on which the front wheel W2 is rotatably mounted in axially fixed position by means of conical roller bearings 44 and 45. An axle shaft 41` for the front wheel W2 extends through the hub sleeve 43 `and has a spline connection at its axially outer end nwith a disk 48 which is secured at its periphery to the rim of the front wheel W2.

Another line shaft' 45 is rotatably mounted on the-front wheel support 1 for rotation on an axis at right angles to the axis of the front wheel W2. the line shaft 43 being rotatably supported in axially xed position by means of a roller bearing 5l and a ball bearing 52 an annular bearing support 53 which is rigidly. secured to the .casing 4I at the rear side; of the latter.: Integrally formed with the line shaft 49 is a bevelgear C which meshes with a bevel gear D on the-:axle shaft 41, the bevel Vgear D being'connected by splines 4t with the axially inner end of the axle shaft 41 within the casing 4I and rotatablyY supported by means of a double row ballbearing 54 in a web 55 of the casing 4l, and by means ofaa roller bearing 5tv in the cover 42.

An intermediate line shaft sectionl5'l `is universally connected at its oppositeendswith 'the line shafts 34 and 49, respectively,I a universal joint 58 connecting the rear end of the intermediate line shaft section51 with thev forwardend of the line shaft 34, and a universal joint59 connecting the forward end of the intermediate line shaft section 51 with the rear end of the line shaft' 49. The forward end of the line shaft 34 hasv a circumferential seriesv of axially extending splines 60, and the universal joint 58 is mounted on the splined forward portion of the lineshaft 34 rfor axial back and forth movement relative to the latter. The universal joint 59, on the otherhand, is mounted on the 4rear end of the line shaft-49 in axially fixed position by means of a cross pin 58. The line shafts 34 and 49 together with the line shaft section 51 and universal joints 58 and 59 form a shaft connection between" the Va'xle housing 4 and the wheel support 1, for driving the front wheel W2, and which shaft connection is flexible and extensible soi as yto accommodate up and down movement of the wheel support 1 relative to the rear axle housing 4.' l

The foregoing explanations regarding the tanel dem drivefmechanism at 'the near side'of the tractor (Fig. l) analogously apply tothe tandem drive mechanism at the far side -of 'the vtractor (Fig. 4), and it will be understood'thatin operationof the tractor driving power may be applied selectively to the drive shaft S of the tandem drive mechanism at .one side, or tothe corresponding drive shaft S at the other side,'or to both drive `shafts simultaneously, inconformitywith well known'principles.

Considering the operation of the `epicyclic gear train X, Y, Z and'of the bevel geartrain A; B, C, D during propulsion of'thetracton'it will be noted that the epicyclic gear train not only serves as a differential between the-wheels Wr and W2 but alsoas a ,transmission gearing between therdrive shaft S and the wheels yW1 and W2, whose gear ratio is ldifferent. from unity. Asshown in ll'ig.,v 3, theepicyclicjgear trai n X,

l"Yfzlis solproportionedthat thegea'rratio be'- tween the sun'gearXand the counter gear Z,

at-'zero 'speed ofthe spider' Y, is larger than unity, and the bevel `gear train A, B, C, D,is so proportioned that the gear ratio between the bevel gears A andY D is substantially equal to the gear ratio which obtains between the counter gear Z and the spider -Y at zero speed of the sun gear X. The rim diameter of the wheel W1 is -equal to the-rim diameter of the wheel W2, and during propulsion of Athetractor on level Aground the rim speed and the rim pull of the wheel W1 will be substantially equal to the rim speed and rim pull of the wheel W2. When the wheels W1 and W2 are thus driven at the same speed, suchspeed is substantially lower'than'the rotary speed of the drive shaft S,the total reduction ratio between the drive shaft S and the wheels'Wi Vand W2 being twice as' large as fthe reduction ratio which obtains between the drive shaft and one of the'wheelsV when the vother wheel is locked against rotation. In the-mecha- 'nism as shown in Fig. 3, the reduction ratio between the drive shaft S and the wheel'Wi, at

zero speed ofthe wheel W2, is equal to the reductionratio between the sun gear X and the spider Y, and the total reduction ratio between the drive shaft Sandv bothwheels W1` and W2 is twice the reduction ratio between the sun gear X and the spider Y.

lIn general terms, the tandem drive vehicle 'disclosed herein comprises a vehicle body having a rearward, transversely extending axle hous-y ing 4, a pair of rear wheels W i'rotatably mounted, respectively, at opposite ends of said axle housing in vertically nnswingable relation thereto, and

parallel link mechanisms at opposite sides, respectively, of the vehicle body, each comprising a wheel support 1 and a pair of upper and lower links 8 and 9 operatively connecting the wheel support with vthe, axle housing y in vertically swingable relation thereto.

The vehicle further comprises a pair offrent Wheels W2 which are rotatably mounted, respectively, on the wheel supports 1 and in tandem relation to the rear wheels W1; a transverse *iequalizer element on a forwardportion of the pivotal connecting means as represented by the' ball and socket joints II, I3 and I2, I4, between the axle housing 4 and the trapezoidal link member at the wide end portion of the latter, secure said link member for swinging movement on a first pivot axis extending longitudinally of the axle housing and transversely of the link member 8 from one of the converging sides thereof to the other. Another link member, as represented by the lower link 9, is pivotally secured at one end thereof to the axle housing 4 at a point of the latter, as shown at I8 in Fig. 1, in vertically spaced relation to the first pivot axis of the trapezoidal link member 8. 'I'he Wheel support 1 and the trapezoidal link member 8 are connected with each other for relative swinging movement on a .second pivot' axisexv other link member which in the illustrated embodiment of the invention is represented byfthe lower link 9, is connected atv its other end with the .wheel support 'I at a point on the latter in vertically spaced relation tothe mentioned second pivot axis, such connection being afforded. in the illustrated embodiment of the invention by the ball and socket joint 2|.

It should be understood that it is not intended to limit the invention to the hereinabove described forms and details, and that the invention includes such other forms and modications as are embraced by the scope of the appended claims.` .i

It is claimed and desired to secure by Letters Patent: ,A if f 1. A tandem drive vehicle comprising, in combination, a vehicle body having a rearward, transversely extending axle housing, a pair Iof vrear wheels rotatably mounted, respectivelyfat opposite ends of said axle housing in vertically nonswingable relation thereto, 'parallel` link mechanisms at opposite sides, respectively, of said vehicle body, each co-mprising a .wheel support and a pair` of uppervand lower` links operatively connecting said wheel support with said axle housing in verticallyI swingable relation thereto, a pair of front wheels rotatably mounted, respectively, on said wheel supports and in tandem relation to said rear wheels, a transverse equalizer element pivoted at its center on alforward part of said vehicle body and bearing at its opposite ends, respectively, upon said wheel supports, and means kfor transmitting driving power to said rear and front'wheels -at--each side of said vehicle body. Y

2. A tandemdrive vehicle comprising, in combination, a vehicle body, a r-ear pair of power driven ground engagingl traction wheels rotatably mounted on and in vertically nonswingable relation to said vehi-cle body, a front pair of power driven ground engaging traction wheels, a wheel support rotatably' mountingA one -of said front pair of traction wheels at one side of said vehicle body, another wheel support rotatably mountingl the :other of said front -pair of traction wheels at the'other side-of said 'vehicle body, a transverse yequalizer Ielement pivoted at its center on a forward part of said vehicle body and bearing at its opposite ends, respectively, upon said wheel supports, and parallel link mechanisms for mounting said wheel supports, respectively, onv` yand in vertically swingable relation to said vehicle body, ea-ch of 4said parallel link mechanisms comprising a trapezoidal link member having relatively wide and narrow end portions, rear pivot means at the wide end of saidl link member and complementary rear pivot means on said vehicle body operative to mount said link member for vertical swinging movement on a rearward horizontal pivot axis extending transversely of said vehicle body and in thek directi-on from one to 'the other of the converging sides of said link member, front pivot means at the narrow end of said link member and complementary front pivot means on the respective wheel support operative to connect said wheel support and said 'link member for relative swinging movement on a forward pivot axis extending parallel to said w"7 rearwardpivot axis,;-.another linkl member hav,- ingVa-pivotioonnection at one of its endswith said vehicle bodyat a point on the latter in vertically spaced relation to said rearward pivot axis, and p-ivot means connecting said other link member Vat its other end With the respectivey Wheel support at a point on the latter in verti- Vcally spaced relation tov said forward pivot axis.

-in thedirection of said rearward pivot axis.

f 4.1-.A tandem drive vehicleas set forthiin claim 2, in which said other link member offeach of said parallel link mechanisms is connected by ,a ball and socket joint with said vehicle body and by :another ball and socket joint withthe respective wheel support.

5. A tandem drive vehicle as set forthrin claim 2,` in WhichA the trapezoidal link member of each of said parallel link mechanisms is connected at its wide end with said vehicle body by a pair of ball and socket joints having centers, respectively, aligned on and spaced from each other in the direction of said rearward pivot axis, and in whichsaid other link member of each of said parallel link mechanisms is connected by a ball and socket joint with said vehicle body and by another ball and socket joint with the .pair of front driving wheels rotatably moun+ ed, independently of Veach other, on said front wheel supports, respectively, and spring means operatively interposed between said main body and said parallellinkstructures for sustaining said main bodyV forwardly of said transverse axis; each of said parallel link structures comprising a pair of upper and lower link members, rear pivot Imeans securing one of said link members in pivotalrelation to said mainbody on an axis 1 xedly extendingpparallel -to i said transverse. axis, and front pivot means connecting Asaid one link member in pivotal relation to Vthe respective lfront Wheel support on another axis xedly extending parallel to said tr-ansverse axis in all positions thereof.

7. In a motor vehicle having a main body and tandem drive mechanisms at opposite sides, respectively, of saidfmain body, the combination of a rear pair of driving wheels mounted on said main body for rotation on a transverse axis xed vertically and horizontally relative to said body, parallel link'structures mounted on said rmain ybody g and presenting yapair of .independently andvertica'uy swingable front wheel supports at-opposite sides, respectively, of said main body. a pair of front driving `Wheels rotatably mounted, independently of each other, on said front wheel supportsrespectively, and spring means operatively interposed betweensaid main body and said parallel link structures for sustaining said main body forwardlyrof said transverse axis; each of said parallel link structures comprising a lpair of upper land lower link mem,-

Vbers, rear pivot means securing said upper link member in pivotal relation to said main. body on an axis xedly extendingparallel to said transverse axis, and front pivot means connectving said upper link member in pivotal relation to the respective front Wheel support on vanother axis xedly extending l parallel .to ,sa-id transverse axis in all'positionsthereof, the .effective axial width of said rear pivot means being greater-than the eiective axial vWidth of said front `pivot means.

EMIL F..NORELIUS.

REFERENCES CITED The following references are of'record inthe le of this patent:

UNITED` STATES PATENTS Number Name Date 1,968,044 Douglass July 22, 1913 1,865,133 Osman 1 June 28, 1932 1,891,642 Harrison Dec. 2O,l 1932 1,983,826 Wilson Dec.. 11, 1934 2,135,619 'Johnston Nov. 8, 1938 l FOREIGN PATENTS Number Country Date 282,017 `Great Britain May 3, 1928 

